Cable Selection And Connections

[333rocky333]

Oh, the T&E is coming from a 63A RCD. SF is 100A.

Bit more detail or a picture of here

Is it a fuse or rcd or both

 

[Darkness]

Its a hager 63 Amp 30mA RCD.


Picture may not be the same but the same principle.

http://www.tlc-direct.co.uk/Products/HGCD263U.html

 

[333rocky333]

Its a hager 63 Amp 30mA RCD.


Picture may not be the same but the same principle.

http://www.tlc-direct.co.uk/Products/HGCD263U.html

That is not suitable to connect to a 100 amp supply, it should be fused down first.

Are you saying then the 40 metres of 16mm twin and earth are protected by the hagar RCD and the 100 amp supply

Or is there a smaller fuse in the 100 amp switchfuse, which I assume is what the SF stands for.

 

[ban-all-sheds]

Or Service Fuse?

 

[Darkness]

Service Fuse is 100A. I'll check tomorrow but come to think of it, I think the T&E is on a 40A MCB which actually makes sense.

 

[ericmark]

Max Amps 16mm cable

• ericmark
• 22 Sep 2008
• 1

Taking the max as 85 amps clipped direct this shows the max amps to maintain 3% volt drop...

Assuming clipped direct as installation method and 3% volt drop the max current is shown in graph using 2.8 mV/A/m as cable volt drop.
As can be seen at 40 amp limited to 60 meters.
The Hager 63 Amp 30mA RCD will mean there is no problem with earth loop impedance but 5500 Watts is 24 amp and can't see how you can draw this on a 120 meter run. Also what external metal parts if the power washer is to be used outside and it is Class I then likely to need TT supply.
This is not a DIY job and to try to do a job like this without calculating everything first is just not on. Plus of course likely if coming from house supply to be Part P.
If Darkness is Part P registered then he should not need us to work it out for him!
Eric [/wiki]

 

[Darkness]

Firstly Part P does not apply to me.

Here are some photos of the two CU's. The first is at the start of the T&E and I would like to note, I got the 63A RCD mixed with another CU I have at another site. The second CU is at the T&E/SWA joining.

 

[ericmark]

Have you read http://www2.theiet.org/Publish/Wire...matters_electrical_installations_outdoors.pdf this may help.
Eric

 

[ban-all-sheds]

The Hager 63 Amp 30mA RCD will mean there is no problem with earth loop impedance

Do the regulations allow the use of RCDs to get around excessive fault loop values with TN supplies?

 

[ricicle]

The Hager 63 Amp 30mA RCD will mean there is no problem with earth loop impedance

Do the regulations allow the use of RCDs to get around excessive fault loop values with TN supplies?

It is acceptable but will obviously not cover PSC issues

 

[Darkness]

btw, my current supply is TT. I don't think I mentioned that.